1. Field of the Invention
The present invention relates to a photovoltaic module and a manufacturing method thereof.
2. Description of Related Art
Recently, as existing energy resources like oil and coal and the like are expected to be exhausted, much attention is increasingly paid to alternative energy sources which can be used in place of the existing energy sources. In the alternative energy sources, solar energy is abundant and has no environmental pollution. Therefore, more and more attention is paid to the solar energy. The solar energy is used in the form of solar heat energy and sunlight energy. The solar heat energy is used to generate steam for rotating a turbine by using solar heat. The sunlight energy is used to convert photons into electrical energy by using a semiconductor property.
A photovoltaic module converting sunlight into electrical energy has a junction structure of a p-type semiconductor and an n-type semiconductor. When light is incident on the photovoltaic module, an electron with a negative electric charge and an electron-hole with a positive electric charge are generated by the interaction between the light and a material constituting the semiconductor of the photovoltaic module. Then, electric current flows while the electron and the electron-hole move.
This is referred to as a photovoltaic effect. Regarding the p-type and the n-type semiconductors, all of which constitute the photovoltaic module, an electron is attracted to the n-type semiconductor and moves to an electrode joined to the n-type semiconductor. An electron-hole is attracted to p-type semiconductor and moves to an electrode joined to the p-type semiconductor. Then, electricity flows outward through the connection between the electrodes by wires.
The photovoltaic module is used for buildings as well as electric-power generation. The building integrated photovoltaic module is installed on the roof, wall or window of a building and generates electric power. The building integrated photovoltaic module is required to have various other features as compared with the electric power generation photovoltaic module. Therefore, many researches are devoted to the building integrated photovoltaic module.
The commercially used building integrated photovoltaic module has a dark black color or, in many cases, has a reddish brown color or an orange color. When the building integrated photovoltaic module is installed on the window of a building, visual fatigue may be easily caused. The building integrated photovoltaic module also degrades aesthetics and does not achieve total harmony well with the building.
Hence, a photovoltaic module is urgently required, which is capable of generating electrical energy by receiving sunlight, of reducing fatigue caused by the installation thereof to a building and of aesthetically achieving harmony with the building.